MAN hastctl

HASTCTL(8) FreeBSD System Manager's Manual HASTCTL(8)

NAME
hastctl -- Highly Available Storage control utility

SYNOPSIS
hastctl create [-d] [-c config] [-e extentsize] [-k keepdirty]
[-m mediasize] name ...
hastctl role [-d] [-c config] all | name ...
hastctl status [-d] [-c config] [all | name ...]
hastctl dump [-d] [-c config] [all | name ...]

DESCRIPTION
The hastctl utility is used to control the behaviour of the hastd(8) dae-
mon.

This utility should be used by HA software like heartbeat or ucarp to
setup HAST resources role when changing from primary mode to secondary or
vice versa. Be aware that if a file system like UFS exists on HAST
provider and primary node dies, file system has to be checked for incon-
sistencies with the fsck(8) utility after switching secondary node to
primary role.

The first argument to hastctl indicates an action to be performed:

create Initialize local provider configured for the given resource.
Additional options include:

-e extentsize Size of an extent. Extent is a block which is
used for synchronization. hastctl maintains a map
of dirty extents and extent is the smallest region
that can be marked as dirty. If any part of an
extent is modified, entire extent will be synchro-
nized when nodes connect. If extent size is too
small, there will be too much disk activity
related to dirty map updates, which will degrade
performance of the given resource. If extent size
is too large, synchronization, even in case of
short outage, can take a long time increasing the
risk of loosing up-to-date node before synchro-
nization process is completed. The default extent
size is 2MB.

-k keepdirty Maximum number of dirty extents to keep dirty all
the time. Most recently used extents are kept
dirty to reduce number of metadata updates. The
default number of most recently used extents which
will be kept dirty is 64.

-m mediasize Size of the smaller provider used as backend stor-
age on both nodes. This option can be omitted if
node providers have the same size on both sides.

role Change role of the given resource. The role can be one of:

init Resource is turned off.

primary Local hastd(8) daemon will act as primary node for the
given resource. System on which resource role is set
to primary can use /dev/hast/ GEOM provider.

secondary Local hastd(8) daemon will act as secondary node for
the given resource - it will wait for connection from
the primary node and will handle I/O requests received
from it. GEOM provider /dev/hast/ will not be
created on secondary node.

status Present status of the configured resources.

dump Dump metadata stored on local component for the configured
resources.

In addition, every subcommand can be followed by the following options:

-c config Specify alternative location of the configuration file. The
default location is /etc/hast.conf.

-d Print debugging information. This option can be specified
multiple times to raise the verbosity level.

FILES
/etc/hast.conf Configuration file for hastctl and hastd(8).
/var/run/hastctl Control socket used by hastctl to communicate with the
hastd(8) daemon.

EXIT STATUS
Exit status is 0 on success, or one of the values described in
sysexits(3) on failure.

EXAMPLES
Initialize HAST provider, create file system on it and mount it.

nodeB# hastctl create shared
nodeB# hastd
nodeB# hastctl role secondary shared

nodeA# hastctl create shared
nodeA# hastd
nodeA# hastctl role primary shared
nodeA# newfs -U /dev/hast/shared
nodeA# mount -o noatime /dev/hast/shared /shared
nodeA# application_start

Switch roles for the shared HAST resource.

nodeA# application_stop
nodeA# umount -f /shared
nodeA# hastctl role secondary shared

nodeB# hastctl role primary shared
nodeB# fsck -t ufs /dev/hast/shared
nodeB# mount -o noatime /dev/hast/shared /shared
nodeB# application_start